The Merseyside club were quick to brand an earlier, £28 million joint offer for the midfielder and the left-back "derisory and insulting" and club officials were eager on Wednesday to dismiss suggestions the England international had asked to be allowed to leave Goodison Park for Old Trafford.

But both the club and manager Roberto Martinez have opted to stay silent when quizzed about a larger offer, while the Spaniard admitted he is coming up with a contingency plan should he lose players in the last few days of the transfer window.

As he had done after Wednesday's Capital One Cup win against Stevenage, Martinez deflected questions in his Thursday press conference when asked about a new offer from United, saying: "I'm not going to talk about any stories and speculation. I'm not going to comment on anything regarding the transfer window in terms of coming in or going out."

Martinez reiterated that Baines had not requested a move to United, now led by former Everton manager David Moyes, but conceded he has considered who to buy should his prized assets leave.

The 39-year-old is expected to return to his former club Wigan with an offer for midfielder James McCarthy and told British daily newspapers: "I've had conversations but not in a formal way."

Everton are also interested in a loan deal for midfielder Gareth Barry should Fellaini leave, sources close to Manchester City told ESPN, and Martinez said: "The way you work in the transfer market is to always think about the unthinkable. You always have to work in a way which means that if the worst was to happen, and you picked up one or two injuries, you need to replace players."

Martinez also warned Fellaini and Baines that their careers might not necessarily improve elsewhere.

He explained: "Players will always like that next challenge and to go to play Champions League football and win trophies. But there are great stories about that. Michael Owen leaves Liverpool to go to Real Madrid to win trophies and Liverpool win the Champions League. In football nothing is guaranteed."